from sys import stdin, stdout

def main():
    line = stdin.readline()
    parts = line.split()
    x = int(parts[0])
    stdout.write('Yes' if x>=30 else 'No')

main() from sys import stdin, stdout def main():
    line = stdin.readline()
    parts = line.split()
    x = int(parts[0])
    stdout.write('Yes' if x>=30 else 'No') main line = stdin.readline() line stdin.readline() stdin.readline stdin readline parts = line.split() parts line.split() line.split line split x = int(parts[0]) x int(parts[0]) int parts[0] parts 0 stdout.write('Yes' if x>=30 else 'No') stdout.write stdout write 'Yes' if x>=30 else 'No' x>=30 x 30 'Yes' 'No' main() main def main():
    line = stdin.readline()
    parts = line.split()
    x = int(parts[0])
    stdout.write('Yes' if x>=30 else 'No') def main():
    line = stdin.readline()
    parts = line.split()
    x = int(parts[0])
    stdout.write('Yes' if x>=30 else 'No') main
from sys import stdin, stdout

def main():
    line = stdin.readline()
    parts = line.split()
    x = int(parts[0])
    stdout.write('Yes' if x>=30 else 'No')

main()